Subcutaneous cavity marking device and method

ABSTRACT

These are subcutaneous cavity marking devices and methods. More particularly, upon insertion into a body, the cavity marking device and method enable one to determine the center, orientation, and periphery of the cavity by radiographic, mammographic, echogenic, or other non-invasive imaging techniques. Also, the device contains a bioabsorbable or non-bioabsorbable marker. The device may be combined with various substances enhancing the radiopaque, mammographic, or echogenic characteristics of the marker or the body allowing it to be observed by any non-invasive imaging techniques. This is further a method of marking a subcutaneous cavity using a bioabsorbable material and a bioabsorbable or non-bioabsorbable marker in conjunction with the material. The method also may combine any of the features as described with the device.

RELATED APPLICATIONS

[0001] This application is a continuation of U.S. Ser. No. 09/285,329filed Apr. 2, 1999, which is a continuation-in-part of U.S. Ser. No.09/220,618, filed Dec. 24, 1998.

FIELD OF THE INVENTION

[0002] This invention is directed to subcutaneous cavity marking devicesand methods. More particularly, a cavity marking device and method isdisclosed that enable one to determine the location, orientation, andperiphery of the cavity by radiographic, mammographic, echographic, orother non-invasive techniques. The invention typically is made up of oneor more resilient bodies and a radiopaque or echogenic marker.

BACKGROUND OF THE INVENTION

[0003] Over 1.1 million breast biopsies are performed each year in theUnited States alone. Of these, about 80% of the lesions excised duringbiopsy are found to be benign while about 20% of these lesions aremalignant.

[0004] In the field of breast cancer, stereotactically guided andpercutaneous biopsy procedures have increased in frequency as well as inaccuracy as modem imaging techniques allow the physician to locatelesions with ever-increasing precision. However, for any given biopsyprocedure, a subsequent examination of the biopsy site is very oftendesirable. There is an important need to determine the location, mostnotably the center, as well as the orientation and periphery (margins)of the subcutaneous cavity from which the lesion is removed.

[0005] In those cases where the lesion is found to be benign, forexample, a follow-up examination of the biopsy site is often performedto ensure the absence of any suspect tissue and the proper healing ofthe cavity from which the tissue was removed. This is also the casewhere the lesion is found to be malignant and the physician is confidentthat all suspect tissue was removed and the tissue in the region of theperimeter or margins of the cavity is “clean”.

[0006] In some cases, however, the physician may be concerned that theinitial biopsy failed to remove a sufficient amount of the lesion. Sucha lesion is colloquially referred to as a “dirty lesion” or “dirtymargin” and requires follow-up observation of any suspect tissue growthin the surrounding marginal area of the initial biopsy site. Thus, are-excision of the original biopsy site must often be performed. In sucha case, the perimeter of the cavity must be identified since the cavitymay contain cancerous cells. Identification of the cavity perimeter isnecessary to avoid the risk of opening the cavity, which could releaseand spread cancerous cells. Moreover, the site of the re-excisedprocedure itself requires follow-up examination, providing furtherimpetus for accurate identification of the location of the re-excisedsite. Therefore, a new marker will be placed after re-excision.

[0007] Prior methods of marking biopsy cavities utilize one or moretissue marking clips as the biopsy site marking device. Most commonly,these marker clips have a “horseshoe” configuration. The marker clipsattach to the walls of the cavity when the free ends or limbs of the“horseshoe” are pinched together, trapping the tissue. This device hassignificant drawbacks.

[0008] For instance, prior to placing the marker clip at the cavitysite, the site must be thoroughly cleaned, typically by vacuum, toremove any residual tissue debris. This minimizes the possibility thatthe marker clip attaches to any loose tissue as opposed to the cavitywall. Once the cavity is prepared, the clip must be examined to ensurethat the limbs of the clip are substantially straight. If the limbs havebeen prematurely bent together, the clip will be discarded since it willmost likely not attach properly to the cavity wall. Actual placement ofthe clip often requires additional vacuum of the cavity wall to draw thewall into the aperture between the limbs of the marking clip so that abetter grip is obtained between the limbs of the clip. Additionally,there is always the possibility that the clip may detach from the cavitywall during or after withdrawal of the tools used to place the clip intothe cavity.

[0009] Aside from the problems inherent in the placement of the markingclip, there are also limitations associated with how well the markingclip can identify a biopsy cavity. As the marking clip must trap tissuefor proper attachment, in cases of endoscopic placement, the clip canonly be placed on a wall of the cavity substantially opposite to theopening of the cavity.

[0010] Moreover, patient concern limits the number of clips that may beplaced in a cavity. As a result, the medical practitioner is forced toidentify the outline of a three dimensional cavity by a single point asdefined by the marking clip. Obviously, determination of the peripheryof a biopsy cavity from one point of the periphery is not possible.

[0011] These limitations are compounded as the biopsy cavity fillswithin a few hours with bodily fluids, which eventually renders thecavity invisible to noninvasive techniques. Another difficulty inviewing the clip stems from the fact that the clip is attached to theside, not the center, of the cavity. This makes determining the spatialorientation and position of the cavity difficult if not impossibleduring follow-up examination. Additionally, during a stereotactic breastbiopsy procedure, the breast is under compression when the marking clipis placed. Upon release of the compressive force, determining thelocation of the clip can be unpredictable, and the orientation as wellas the location of the periphery of the cavity are lost.

[0012] The marker clip does not aid in the healing process of the biopsywound. Complications may arise if the marker strays from its originalplacement site. As described above, if a re-excision of the site isrequired, the marker clip may also interfere when excision of a targetlesion is sought.

[0013] Other devices pertaining to biopsy aids are directed to assistingin the healing and closure of the biopsy wound; thus they do not aid theclinical need or desirability of accurately preserving the location andorientation of the biopsy cavity. See, e.g., U.S. Pat. Nos. 4,347,234,5,388,588, 5,326,350, 5,394,886, 5,467,780, 5,571,181, and 5,676,146.

SUMMARY OF THE INVENTION

[0014] This invention relates to devices and procedures forpercutaneously marking a biopsy cavity. In particular, the inventivedevice is a biopsy cavity-marking body made of a resilient, preferablybioabsorbable material having at least one preferably radiopaque orechogenic marker. The device may take on a variety of shapes and sizestailored for the specific biopsy cavity to be filled. For example, thedevice in its simplest form is a spherical or cylindrical collagensponge having a single radiopaque or echogenic marker located in itsgeometric center. Alternatively, the body may have multiple componentslinked together with multiple radiopaque or echogenic markers.

[0015] A further aspect of the invention allows the marker or the body,singly or in combination, to be constructed to have a varying rate ofdegradation or bioabsorption. For instance, the body may be constructedto have a layer of bioabsorbable material as an outer “shell.”Accordingly, prior to degradation of the shell, the body is palpable.Upon degradation of the shell, the remainder of the body would degradeat an accelerated rate in comparison to the outer shell.

[0016] The device may additionally contain a variety of drugs, such ashemostatic agents, pain-killing substances, or even healing ortherapeutic agents that may be delivered directly to the biopsy cavity.Importantly, the device is capable of accurately marking a specificlocation, such as the center, of the biopsy cavity, and providing otherinformation about the patient or the particular biopsy or devicedeployed.

[0017] The device is preferably, although not necessarily, deliveredimmediately after removal of the tissue specimen using the same deviceused to remove the tissue specimen itself. Such devices are described inpending U.S. patent application Ser. No. 09/145,487 (Attorney Docket No.41269-20002.00), filed Sep. 1, 1998 and entitled “PERCUTANEOUS TISSUEREMOVAL DEVICE”, and pending U.S. patent application Ser. No. 09/184,766(Attorney Docket No. 41269-20001.20), filed Nov. 2, 1998 and entitled“EXPANDABLE RING PERCUTANEOUS TISSUE REMOVAL DEVICE” the entirety ofeach are which hereby incorporated by reference. The device iscompressed and loaded into the access device and percutaneously advancedto the biopsy site where, upon exiting from the access device, itexpands to substantially fill the cavity of the biopsy. Follow-upnoninvasive detection techniques, such as x-ray mammography orultrasound may then be used by the physician to identify, locate, andmonitor the biopsy cavity site over a preferred period of time.

[0018] The device is usually inserted into the body either surgicallyvia an opening in the body cavity, or through a minimally invasiveprocedure using such devices as a catheter, introducer or similar typedevice. When inserted via the minimally invasive procedure, theresiliency of the body allows the device to be compressed upon placementin a delivery device. Upon insertion of the cavity marking device intothe cavity, the resiliency of the body causes the cavity marking deviceto self-expand, substantially filling the cavity. The resiliency of thebody can be further predetermined so that the body is palpable, thusallowing tactile location by a surgeon in subsequent follow-upexaminations. Typically, the filler body is required to be palpable forapproximately 3 months. However, this period may be increased ordecreased as needed.

[0019] The expansion of the resilient body can be aided by the additionof a bio-compatible fluid which is absorbed into the body. For instance,the fluid can be a saline solution, a painkilling substance, a healingagent, a therapeutic fluid, or any combination of such fluids. The fluidor combination of fluids may be added to and absorbed by the body of thedevice before or after deployment of the device into a cavity. Forexample, the body of the device may be pre-soaked with the fluid andthen delivered into the cavity. In this instance, the fluid aids theexpansion of the body of the device upon deployment. Another example isprovided as the device is delivered into the cavity without beingpre-soaked. In such a case, fluid is delivered into the cavity after thebody of the device is deployed into the cavity. Upon delivery of thefluid, the body of the device soaks the fluid, thereby aiding theexpansion of the cavity marking device as it expands to fit the cavity.The fluid may be, but is not limited to being, delivered by the accessdevice.

[0020] By “bio-compatible fluid” what is meant is a liquid, solution, orsuspension that may contain inorganic or organic material. For instance,the biocompatible fluid is preferably saline solution, but may be wateror contain adjuvants such as medications to prevent infection, reducepain, or the like. Obviously, the liquid is intended to be a type thatdoes no harm to the body.

[0021] After placement of the cavity marking device into the cavity, thebioabsorbable body degrades at a predetermined rate. As the body of thecavity marking device is absorbed, tissue is substituted for thebioabsorbable material. Moreover, while the body degrades, the marker,which is usually suspended substantially in the volumetric center of thebody of the device, is left in the center of the cavity. Thus, during asubsequent examination, a medical practitioner having knowledge of thedimensions of the body of the cavity marking device can determine thelocation as well as the periphery of the biopsy cavity. The orientationof the cavity is self-evident as the marker is left in substantially thecenter of the cavity. For the case where multiple markers are used, themarkers are usually placed in a manner showing directionality.

[0022] Both the body and the marker can be made, via radiopaque orechogenic coatings or in situ, to degrade and absorb into the patient'sbody over a predetermined period of time. It is generally preferred thatif the marker's radiopacity or echogenicity is chosen to degrade overtime, such degradation does not take place within at least one yearafter implantation of the inventive device. In this way, if a new lumpor calcification (in the case of a breast biopsy) is discovered afterthe biopsy, such a marker will allow the physician to know the relationof such new growth in relation to the region of excised tissue. On theother hand, and as discussed below, a bioabsorption period of threemonths is preferred for any such coatings on the perimeter of the bodyitself.

[0023] This invention further includes the act of filling the biopsycavity with a bioabsorbable liquid, aerosol or gelatinous material,preferably gelatinous collagen, allowing the material to partiallysolidify or gel and then placing a marker, which may have aconfiguration as described above, into the center of the bioabsorbablematerial. The gel may also be made radiopaque or echogenic by theaddition of radiopaque materials, such as barium- or bismuth-containingcompounds and the like, as well as particulate radio-opaque fillers,e.g., powdered tantalum or tungsten, barium carbonate, bismuth oxide,barium sulfate, to the gel.

[0024] This method may be combined with any aspect of the previouslydescribed devices as needed. For instance, one could insert a hemostaticor painkilling substance as described above into the biopsy cavity alongwith the bioabsorbable material. Alternatively, a bioabsorbable markercould be inserted into a predetermined location, such as the center, ofthe body of bioabsorbable material.

[0025] It is within the scope of this invention that either or both ofthe marker or markers and the bioabsorbable body may be radioactive, ifa regimen of treatment using radioactivity is contemplated.

[0026] This procedure may be used in any internal, preferably soft,tissue, but is most useful in breast tissue, lung tissue, prostatetissue, lymph gland tissue, etc. Obviously, though, treatment anddiagnosis of breast tissue problems forms the central theme of theinvention.

[0027] In contrast to the marker clips as described above, the cavitymarking device has the obvious advantage of marking the geometric centerof a biopsy cavity. Also, unlike the marking clip which has thepotential of attaching to loose tissue and moving after initialplacement, the marking device self-expands upon insertion into thecavity, thus providing resistance against the walls of the cavitythereby anchoring itself within the cavity. The marking device may beconfigured to be substantially smaller, larger, or equal to the size ofthe cavity, however, in some cases the device will be configured to belarger than the cavity. This aspect of the biopsy marking deviceprovides a cosmetic benefit to the patient, especially when the biopsyis taken from the breast. For example, the resistance provided by thecavity marking device against the walls of the cavity may minimize any“dimpling” effect observed in the skin when large pieces of tissue areremoved, as, for example, during excisional biopsies.

[0028] Although the subcutaneous cavity marking device and methoddescribed above are suited for percutaneous placement of the markerwithin a biopsy cavity it is not intended that the invention is limitedto such placement. The device and method are also appropriate forintra-operative or surgical placement of the marker within a biopsycavity.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1A illustrates a tissue cavity marking device with aspherical body and a single centrally-located marker.

[0030]FIG. 1B shows a tissue cavity marking device with a cylindricalbody and two ring-shaped markers aligned near the cylinder'slongitudinal axis.

[0031]FIG. 1C shows another tissue cavity marking device with amulti-faced or irregular body and a single centrally-located marker.

[0032]FIG. 1D illustrates a tissue cavity marking device with a bodyhaving pores.

[0033]FIG. 1E is a partial cross-sectional view of FIG. 1D.

[0034]FIG. 1F illustrates a tissue cavity marking device with a bodyhaving an outer shell of a bioabsorbable material.

[0035] FIGS. 2A-2F illustrate various configurations of the marker.

[0036]FIG. 3A illustrates a cavity marking device having multiple bodycomponents traversed by a single wire or suture marker, or multiplewires or suture markers.

[0037]FIG. 3B illustrates a cavity marking device having a helicallywound wire or suture marker.

[0038]FIG. 3C illustrates a cavity marking device having wire or suturemarkers on the perimeter of the body.

[0039]FIG. 3D illustrates a cavity marking device having wire or markerson the ends of the body.

[0040] FIGS. 4A-4C illustrate a method of marking a biopsy tissue cavitywith the device of the present invention.

[0041] FIGS. 4D-4F illustrate a method of marking a biopsy tissue cavitywith the device of the present invention wherein a bio-compatible fluidis delivered to the cavity marking device after placement.

[0042] FIGS. 4G-4I illustrate a method of marking a biopsy tissue cavitywith the device of the present invention wherein a bio-compatible fluidis used to push the cavity marking device out of the access device andinto the biopsy tissue cavity.

[0043] FIGS. 4J-4K illustrate a method of marking a biopsy tissue cavitywith the device of the present invention wherein the body material ofthe marking device is deposited into the biopsy cavity prior to theplacement of the marker within the biopsy device.

[0044] FIGS. 5A-B illustrate a spherical wire marking device fordeployment without a filler body into a tissue cavity.

[0045]FIG. 5C illustrates a cylindrical wire marking device fordeployment without a filler body into a tissue cavity.

[0046] FIGS. 5D-E illustrate a helical coil wire marking device fordeployment without a filler body into a tissue cavity.

DETAILED DESCRIPTION OF THE INVENTION

[0047] FIGS. 1A-1C show various configurations of a preferredsubcutaneous cavity marking device of the present invention. Here themarking device (100) is displayed as having either a generally sphericalbody (102) (FIG. 1A), a generally cylindrical body (104) (FIG. 1B), or amulti-faced or irregular body (106) (FIG. 1C). In general, it is withinthe scope of this invention for the body to assume a variety of shapes.For example, the body may be constructed to have substantially curvedsurfaces, such as the preferred spherical (102) and cylindrical (104)bodies of FIGS. 1A and 1B, respectively. The body may have conical orellipsoidal, etc. shapes as well. It is further within the scope of thisinvention for the body to have substantially planar surfaces, such aspolyhedric (i.e. cubic, tetrahedral, etc.) or prismatic, etc. forms.Finally, the body may also have an irregular or random shape, in thecase of a gel, combining features of various curved and planar surfaces.Body (106) of FIG. 1C is an example of such an irregular body shape. Theparticular body shape will be chosen to best match to the biopsy cavityin which the device is placed. However, it is also contemplated that thebody shape can be chosen to be considerably larger than the cavity.Therefore, expansion of the device will provide a significant resistanceagainst the walls of the cavity. Moreover, the aspect ratio of thedevice is not limited to what is displayed in the figures. For example,the cylindrical body (104) may have a shorter or longer length asrequired.

[0048] In the bodies of FIGS. 1A and 1C, the generally spherical marker(150) is located at or near the geometric center of the body. Such aconfiguration will aid the physician in determining the exact locationof the biopsy cavity, even after the body degrades and is absorbed intothe human or mammalian body.

[0049] In the case of the ring-shaped markers (154) of FIG. 1B, they aregenerally aligned along the longitudinal axis (114) of body (104). Notethat although the ring-shaped markers (154) are spatially oriented sothat the longitudinal axis (114) of the body (104) lies along thelongitudinal axes (not shown) of each marker (154), each marker mayindividually or together assume a wide variety of random orpredetermined spatial orientations other than the aligned orientation asseen in FIG. 1C. It can be appreciated that any asymmetric marker suchas marker (154) is useful in aiding a physician to determine the spatialorientation of the deployed inventive device.

[0050] Obviously, marker (150), (154) may reside in locations other thanthose demonstrated in FIGS. 1A-1C. It is, however, preferred thatmarkers (150), (154) dwell in a predetermined, preferably central,location and orientation in the device body so to aid the physician indetermining the location and orientation of the biopsy cavity. Themarkers herein described may be affixed to the interior or on thesurface of the body by any number of suitable methods. For instance, themarker may be merely suspended in the interior of the body (especiallyin the case where the body is a gel), it may be woven into the body(especially in the case where the marker is a wire or suture), it may bepress fit onto the body (especially in the case where the marker is aring or band), or it may affixed to the body by a biocompatibleadhesive. Any suitable means to affix or suspend the marker into thebody in the preferred location is within the scope of the presentinvention.

[0051] Tissue regrowth in a particular orientation can also be promotedby a body design shown in FIG. 1D. Here, body (110) contains a number ofpores (138) through which tissue may grow. The pores may also be alignedin a substantially parallel fashion, traversing the thickness of thebody so that tissue may regrow from one side of the body through to theother side. This is demonstrated in inset FIG. 1E, which shows a portion(130) of FIG. 1D in partial longitudinal cross section, complete withpores (138) traversing through the thickness of portion (130). Suchpores (138) can be parallel to each other as shown in FIG. 1E, or theymay be perpendicularly, radially, or even randomly oriented in thedevice body.

[0052] A trio of markers is also shown in FIG. 1D evenly aligned alongthe body longitudinal axis (140). Barb marker (156), spherical marker(150), and ring-shaped marker (154) demonstrate the use of differentmultiple markers in a single body (110). As previously described, such adesign helps a physician to determine the spatial orientation of theinventive device when it is deployed in a biopsy cavity. Although thebarb marker (156) is illustrated in a ‘V’ configuration, it is animportant aspect of the barb marker (156) to have a shape that isclearly not spherical. This allows the barb marker (156) to be easilydistinguished from calcifications that may be observed during anynon-invasive imaging techniques.

[0053]FIG. 1F depicts a further embodiment of the present invention inwhich body (112) is enveloped in a outer shell (142) consisting of alayer of bioabsorbable material such those mentioned above. Thisconfiguration allows the perimeter of the biopsy cavity to be marked toavoid exposing the cavity, in the case of a “dirty” margin wherere-excision may be necessary, to remaining cancerous cells as the tissuebegins to re-grow into the cavity. Such a shell (142) can be radiopaqueand/or echogenic in situ, or it may be augmented with an additionalcoating of an echogenic and/or radiopaque material. The shell (142) canalso be made to be palpable so that the physician or patient can befurther aided in determining the location and integrity of the implantedinventive device.

[0054] Shell (142) may be designed to have a varying bioabsorption ratedepending upon the thickness and type of material making up the shell(142). In general, the shell can be designed to degrade over a periodranging from as long as a year or more to as little as several months,weeks, or even days. It is preferred that such a bioabsorbable shell bedesigned to degrade between two and six months; especially preferred isthree months. In the design of FIG. 1F, interior (144) of body (112) maybe a cross-linked, collagenous material that is readily absorbed by thehuman or mammalian body once the shell (142) degrades. Interior (144)may be filled with a solid or gelatinous material that can be optionallymade radiopaque by any number of techniques herein described.

[0055] As will be described in additional detail with respect to FIGS.2A-2F, marker (150) in the device shown in FIG. 1F may be permanentlyradiopaque or echogenic, or it also may be bioabsorbable and optionallycoated with a radiopaque and/or echogenic coating that similarlydegrades over a predetermined period of time. It is more important froma clinical standpoint that the marker remain detectable eitherpermanently or, if the patient is uncomfortable with such a scenario,for at least a period of about one to five years so that the physicianmay follow up with the patient to ensure the health of the tissue in thevicinity of the biopsy cavity. Especially preferable is a marker whoseradiopacity or echogenicity lasts from between about one and threeyears.

[0056] Each of the bodies depicted in FIGS. 1A-1E may be made from awide variety of solid, liquid, aerosol-spray, spongy, or expandinggelatinous bioabsorbable materials such as collagen, cross-linkedcollagen, regenerated cellulose, synthetic polymers, synthetic proteins,and combinations thereof. Also contemplated is a body made from afibrin-collagen matrix, which further prevent unnecessary bleeding, andminimizes the possibility of hematoma formation.

[0057] Examples of synthetic bioabsorbable polymers that may be used forthe body of the device are polyglycolide, or polyglycolic acid (PGA),polylactide, or polylactic acid (PLA), poly ε-caprolactone,polydioxanone, polylactide-co-glycolide, e.g., block or randomcopolymers of PGA and PLA, and other commercial bioabsorbable medicalpolymers. Preferred is spongy collagen or cellulose. As mentioned above,materials such as hemostatic and pain-killing substances may beincorporated into the body and marker of the cavity marking device. Theuse of hemostasis-promoting agents provides an obvious benefit as thedevice not only marks the site of the biopsy cavity but it aids inhealing the cavity as well. Furthermore, such agents help to avoidhematomas. These hemostatic agents may include AVITENE MicrofibrillarCollagen Hemostat, ACTIFOAM collagen sponge, sold by C. R. Bard Inc.,GELFOAM, manufactured by Upjohn Company, SURGICEL Fibrillar from EthiconEndosurgeries, Inc., and TISSEEL VH, a surgical fibrin sealant sold byBaxter Healthcare Corp. The device may also be made to emit therapeuticradiation to preferentially treat any suspect tissue remaining in oraround the margin of the biopsy cavity. It is envisioned that the markerwould be the best vehicle for dispensing such local radiation treatmentor similar therapy. Also, the body itself may be adapted to haveradiopaque, echogenic, or other characteristics that allow the body tobe located by non-invasive technique without the use of a marker. Suchcharacteristics permit the possibility of locating and substantiallyidentifying the cavity periphery after deployment but prior toabsorption of the device. Furthermore, an echogenic coating may beplaced over the radiopaque marker to increase the accuracy of locatingthe marker during ultrasound imaging.

[0058] FIGS. 2A-2F illustrate various forms of the marker (110). Themarker (110) may be in the form of a sphere (150) (FIG. 2A), a hollowsphere (152) (FIG. 2B), a ring or band (154) (FIG. 2C), a barb (156)(FIG. 2D), or a flexible suture or flexible wire (158) (FIG. 2E). Also,the marker may have a distinguishing mark (170) (FIG. 2F). As mentionedabove, the barb (156) is illustrated in FIG. 2D as having a “V” shape.The barb (156) is intended to distinguish the marker from calcificationswhen viewed under non-invasive imaging techniques. As such, the barb(156) is not limited to the “V” shape, rather it has a shape that iseasily distinguishable from a spherical or oval calcification.

[0059] The hollow sphere (152) marker design of FIG. 2B is moresusceptible to detection by ultrasound than the solid sphere (150) ofFIG. 2A. Such sphere markers (150, 152) can be a silicon bead, forinstance. In the case of a ring or band marker (154) seen in FIG. 2C,the body of the cavity marking device may be woven or placed through theband/ring (154). The marker may also be a wire or suture (158) as shownin FIG. 2E and as discussed in greater detail below. In such a case, themarker (158) may be affixed to the exterior perimeter of the body by anadhesive or woven through the body. Another improvement may arise fromthe marker wire or suture (158) being configured in a particular patternwithin the body of the device, e.g., wrapping around the body in ahelical manner. Further, the suture or wire marker can be deployed as aloosely wound ball or mass of suture that when deployed into a tissuecavity, fills the cavity. The suture or wire can also looped through theband/ring (154); in this configuration (not shown), the suture or wirecan also act as the body of the inventive device. The suture or wire(158) is flexible to facilitate the expansion of the body while in thecavity. In the case of the marker (150) shown in FIG. 2F, distinguishingor identifying mark (170) can be in the form of simple marks as shown,or it may be one or more numbers, letters, symbols, or combinationsthereof. These marks (160) are preferably located in more than onelocation on the marker (150) so that the marker may be readily andsimply identified from multiple orientations under a variety of viewingconditions. Such a mark (170) can be used to identify the patient andher condition, provide information about the marker and body of thetissue cavity marking device, provide information about thecircumstances and date of the implantation, who performed the procedure,where the procedure was performed, etc. In the case of multiple biopsysites, this distinguishing mark (170) permits one to differentiate andidentify each different site. The mark (170) may be applied via anynumber of techniques such as physical inscription, physical or plasmadeposition, casting, adhesives, etc. The mark (170) may also be anelectronic chip providing any necessary information in electronic formthat can be remotely detected by appropriate means.

[0060] An important aspect of the invention is that the marker may beradiopaque, echogenic, mammographic, etc. so that it can be located bynon-invasive techniques. Such a feature can be an inherent property ofthe material used for the marker. Alternatively, a coating or the likecan be added to the marker to render the marker detectable or to enhanceits detectability. For radiopacity, the marker may be made of anon-bioabsorbable radiopaque material such as platinum,platinum-iridium, platinum-nickel, platinum-tungsten, gold, silver,rhodium, tungsten, tantalum, titanium, nickel, nickel-titanium, theiralloys, and stainless steel or any combination of these metals. Bymammographic we mean that the component described is visible underradiography or any other traditional or advanced mammography techniquein which breast tissue is imaged.

[0061] As previously discussed, the marker can alternatively be made ofor coated with a bioabsorbable material. In this case, the marker can,for instance, be made from an additive-loaded polymer. The additive is aradiopaque, echogenic, or other type of substance that allows for thenon-invasive detection of the marker. In the case of radiopaqueadditives, elements such as barium- and bismuth-containing compounds, aswell as particulate radio-opaque fillers, e.g., powdered tantalum ortungsten, barium carbonate, bismuth oxide, barium sulfate, etc. arepreferred. To aid in detection by ultrasound or similar imagingtechniques, any component of the device may be combined with anechogenic coating. One such coating is ECHO-COAT from STS Biopolymers.Such coatings contain echogenic features which provide the coated itemwith an acoustically reflective interface and a large acousticalimpedance differential. As stated above, an echogenic coating may beplaced over a radiopaque marker to increase the accuracy of locating themarker during ultrasound imaging.

[0062] Note that the radiopacity and echogenicity described herein forthe marker and the body are not mutually exclusive. It is within thescope of the present invention for the marker or the body to beradiopaque but not necessarily echogenic, and for the marker or the bodyto be echogenic but not necessarily radiopaque. It is also within thescope of the invention that the marker and the body are both capable ofbeing simultaneously radiopaque and echogenic. For example, if aplatinum ring marker were coated with an echogenic coating, such amarker would be readily visible under x-ray and ultrasonic energy. Asimilar configuration can be envisioned for the body or for a bodycoating.

[0063] The marker is preferably large enough to be readily visible tothe physician under x-ray or ultrasonic viewing, for example, yet besmall enough to be able to be percutaneously deployed into the biopsycavity and to not cause any difficulties with the patient. Morespecifically, the marker will not be large enough to be palpable or feltby the patient.

[0064] Another useful version of the invention is shown in FIG. 3A. Inthis device, there are several cylindrical body members (302); however,there is no limit to the number of body members that can make up thedevice. The body members (302) can individually or together take on avariety of sizes and shapes as discussed above depending on thecharacteristics of the biopsy cavity to be filled. The body members(302) may uniformly or in combination be made of one or more materialssuitable for use in a biopsy cavity as previously described.

[0065] Here one or more markers may traverse two or more body membersegments through the interior of the body members (302) as shown in FIG.3A. Here, markers (318) are located substantially parallel to thelongitudinal axis (320) of each right cylindrical body member (302) intheir interior, connecting each body member (302) while marking theirgeometric center as between the markers. Such a marker (318) may be usedin conjunction with the other markers as described above and may also beaccompanied by one or more additional markers arranged randomly or in apredetermined pattern to variously mark particular sections of thedevice. Alternately, such a marker may, singly or in combination withother markers, be affixed on or near the surface of the sponge so as tomark the perimeter of the body member (302).

[0066] Of course, when used in conjunction with other connectingmarkers, marker (318) need not necessarily connect each body member; itmay be used solely to indicate the orientation or location of eachindividual sponge or the entire device, depending on the material,geometry, size, orientation, etc. of marker (318). When not used in thisconnecting function, therefore, marker (318) need not traverse two bodymembers (302) as shown in FIG. 3A.

[0067] A variety of patterns can be envisioned in which all or part ofthe perimeter of the sponge body is marked. For example, a marker (322)can wrap around the body (302) in a helical pattern (FIG. 3B), or it canbe used in conjunction with other markers (324) in a pattern parallel tothe longitudinal axis (320) of the body (302) (FIG. 3C). Another usefulperimeter marking pattern is shown in FIG. 3D, where marker segments(326) are affixed at or near the surface of the circular bases of thecylindrical body (302) in a cross pattern, indicating the ends of thesponge and their center. As seen from the figures, the marker(s) may,but do not necessarily, have some texture. Any marker pattern, internalor external to the body, is within the scope of the present invention.For the applications depicted in FIGS. 3A-3D, it is preferred that themarker be a radiopaque or echogenic wire or suture.

[0068] Another possible configuration is obtained by combining thesuture or wire markers (158) in a body with any other type marker (150,152, 154, or 156) or vice versa. For example, in FIG. 3B, a sphericalmarker (150) may be placed in the center of the cylindrical body (302.)Therefore, the cylindrical body (302) would contain the suture or wiremarker (322) wrapped helically adjacent to the outer perimeter, and amarker (150) would be placed in the center of the cylindrical body(302). Such a combination may be obtained with any of the body andmarker configurations as defined above.

[0069] Also, turning back to the marking device (100) in FIG. 1A or themarking device (100) of FIG. 1B, the markers (150 or 154) may besubstituted with one or more suture or wire markers (158) preferably,but not exclusively, extending through the center and pointing radiallyaway from the center. This configuration allows marking of the cavityperimeter and establishing of the directionality of the cavity itself.

[0070] Any of the previously-described additional features of theinventive device, such as presence of pain-killing or hemostatic drugs,the capacity for the marker to emit therapeutic radiation for thetreatment of various cancers, the various materials that may make up themarker and body, as well as their size, shape, orientation, geometry,etc. may be incorporated into the device described above in conjunctionwith FIGS. 3A-3D.

[0071] Turning now to FIGS. 4A-4C, a method of delivering the inventivedevice of FIG. 1A is shown. FIG. 4A details the marking device (402)just prior to delivery into a tissue cavity (404) of human or othermammalian tissue, preferably breast tissue (406). As can be seen, thestep illustrated in FIG. 4A shows a suitable tubular percutaneous accessdevice (400), such as a catheter or delivery tube, with a distal end(408) disposed in the interior of cavity (404). As previously described,the marking device (402) may be delivered percutaneously through thesame access device (400) used to perform the biopsy in which tissue wasremoved from cavity (404). Although this is not necessary, it is lesstraumatic to the patient and allows more precise placement of themarking device (402) before fluid begins to fill the cavity (400).

[0072] In FIG. 4B, marking device (402) is shown being pushed out of thedistal end (408) of access device (400) by a pusher (412) andresiliently expanding to substantially fill the tissue cavity (404).

[0073] Finally, in FIG. 4C, access device (400) is withdrawn from thebreast tissue, leaving marking device (402) deployed to substantiallyfill the entire cavity (404) with radiopaque or echogenic marker (410)suspended in the geometric center of the marking device (402) and thecavity (404). As mentioned above, the marking device (402) may be sizedto be larger than the cavity (404) thus providing a significantresistance against the walls of the cavity (404).

[0074] FIGS. 4D-4F show a method of delivering the marking device (402)into a tissue cavity (404) by a plunger (414) that is capable of bothadvancing the marking device (402) and delivering a bio-compatible fluid(416). The “biocompatible fluid” is a liquid, solution, or suspensionthat may contain inorganic or organic material. The fluid (416) ispreferably a saline solution, but may be water or contain adjuvants suchas medications to prevent infection, reduce pain, or the like.Obviously, the fluid (416) is intended to be a type that does no harm tothe body.

[0075]FIG. 4D details the marking device (402) prior to delivery intothe tissue cavity (404). In FIG. 4E, a plunger (414) pushes the markingdevice (402) out of the access device (400). Upon exiting the accessdevice (400) the marking device (402) begins resiliently expanding tosubstantially fill the cavity (404).

[0076]FIG. 4F shows the plunger (414) delivering the bio-compatiblefluid (416) into the cavity (404). The fluid (416) aids the markingdevice (402) in expanding to substantially fill the cavity (404). Inthis example, the bio-compatible fluid (416) is delivered subsequent tothe placement of the marking device (402) in the cavity (404). Themarking device (402) may also be soaked with fluid (416) prior toplacement in the cavity (404).

[0077] FIGS. 4G-4I show another method of delivering the marking device(402) into the tissue cavity (404) by using the bio-compatible fluid(416) as the force to deliver the marking device (402) into the tissuecavity (404).

[0078]FIG. 4G details the marking device (402) prior to delivery intothe tissue cavity (404). FIG. 4H illustrates flow of the bio-compatiblefluid (416) in the access device (400), the fluid (416) flow then pushesthe marking device (402) out of the access device (400).

[0079]FIG. 4I shows the delivery device (400) continuing to deliver thebio-compatible fluid (416) into the cavity (404). The fluid (416) aidsthe marking device (402) in expanding to substantially fill the cavity(404). In this example, the bio-compatible fluid (416) is deliveredafter the placement of the marking device (402) in the cavity (404)although the invention is not limited to the continued delivery of thefluid (416).

[0080] FIGS. 4J-4K shows the method of delivering the body (418) of thecavity marking device directly into the cavity (404) prior to theplacement of the marker (410) in the device (402).

[0081]FIG. 4J shows the deposit of the body material (418) into thecavity (404). In this case the body material (418) may be a gel typematerial as described above. FIG. 4K details the filling of the cavity(404) with the body material (418). At this point, the delivery device(not shown in FIG. 4K) may be withdrawn. FIG. 4L details the placementof the marker (410) into the body material (418).

[0082] FIGS. 5A-5E show yet another version of the invention in which amarker, preferably consisting of a radiopaque or echogenic wire, isdeployed alone into a tissue cavity without the use of any body. In thisdevice, the marker can be made of a shape memory material, such as anickel-titanium alloy, which when deployed into the biopsy cavity,assumes a predetermined configuration to substantially fill the cavity,mark the cavity location and margin, and indicate the orientation of themarker inside the cavity.

[0083] In FIG. 5A, marker (500) is a three-dimensional sphere consistingof two rings (502), (504) pivotally connected at ends (506), (508) so toassume a spherical shape. Such a marker can be made of a shape memorymetal so that when it is placed in a deployment tube (510) shown in FIG.5B, marker (500) assumes a collapsed profile suitable for deploymentthrough tube (510) by pusher (512). Upon exiting into the tissue cavity(not shown), marker (500) assumes the spherical shape of FIG. 5A to fillthe cavity. The marker (500) may also be shaped into any similar shapesuch as an ellipsoidal shape.

[0084] Turning now to FIG. 5C, a marker (520) in the form of a wirecylinder is shown. Again, this device is structurally configured toassume the depicted cylindrical configuration when deployed in thetissue cavity, but may be (as described above) “collapsed” into adeployment tube for percutaneous delivery. This device is especiallysuitable for marking the distal and proximal ends of the tissue cavitydue to its asymmetrical shape.

[0085]FIG. 5D shows a shape memory marker (530) in the form of a helicalcoil deployed into tissue cavity (532). Again, as seen in FIG. 5E, sucha marker (530) may be deployed through delivery tube (510) by pusher(512) in a substantially elongated, straightened form, only tosubstantially assume the shape of the cavity (532) as shown in FIG. 5D.Any suitable delivery device or pusher (512) capable of deploying marker(530) into cavity (532) is within the scope of this invention.

[0086] Each of the markers shown in FIGS. 5A-5E is preferably a shapememory material coated or supplemented with a radiopacity-enhancingmaterial, such as gold, platinum, or any other radiopaque materialherein discussed. The markers may singly, or in combination with beingradiopaque, be echogenic or be made echogenic by any of the materials ormethods herein described.

[0087] From the foregoing, it is understood that the invention providesan improved subcutaneous cavity marking device and method. While theabove descriptions have described the invention for use in the markingof biopsy cavities, the invention is not limited to such. One suchapplication is evident as the invention may further be used as alumpectomy site marker. In this use, the cavity marking device yield animproved benefit by marking the perimeter of the lumpectomy cavity.

[0088] The invention herein has been described by examples and aparticularly desired way of practicing the invention has been described.However, the invention as claimed herein is not limited to that specificdescription in any manner. Equivalence to the description as hereinafterclaimed is considered to be within the scope of protection of thispatent.

We claim as our invention:
 1. A subcutaneous cavity marking devicecomprising: (a) at least one filler body comprising a resilientbioabsorbable material, and (b) at least one marker.
 2. The device ofclaim 1 wherein the at least one marker comprises a non-bioabsorbablematerial.
 3. The device of claim 2 wherein the marker comprises amaterial selected from the group consisting of platinum, iridium,nickel, tungsten, tantalum, gold, silver, rhodium, titanium, alloysthereof, and stainless steel.
 4. The device of claim 1 wherein the atleast one marker comprises a second bioabsorbable material.
 5. Thedevice of claim 4 wherein the second bioabsorbable material comprises apolymer having a radiopaque additive.
 6. The device of claim 5 whereinthe radiopaque additive is selected from the group consisting ofbarium-containing compounds, bismuth-containing compounds, powderedtantalum, powdered tungsten, barium carbonate, bismuth oxide, and bariumsulfate.
 7. The device of claim 1 wherein the at least one marker isradiopaque.
 8. The device of claim 1 wherein the at least one body isradiopaque.
 9. The device of claim 1 wherein the at least one marker isechogenic.
 10. The device of claim 1 wherein the at least one body isechogenic.
 11. The device of claim 1 wherein the at least one marker ismammographic.
 12. The device of claim 1 wherein the at least one body ismammographic.
 13. The device of claim 1 wherein the at least one body ispalpable.
 14. The device of claim 1 wherein the marker is located withinan interior of the at least one body.
 15. The device of claim 1 whereinthe marker is substantially located within a geometric center of the atleast one body.
 16. The device of claim 1 additionally comprising a painkilling substance.
 17. The device of claim 1 additionally comprising ahemostatic substance.
 18. The device of claim 1 wherein thebioabsorbable material is selected from the group consisting ofcollagen, regenerated cellulose, synthetic polymers and syntheticproteins.
 19. The device of claim 1 wherein the marker has a form of asphere.
 20. The device of claim 19 wherein the sphere is hollow.
 21. Thedevice of claim 1 wherein the marker has a form of a band.
 22. Thedevice of claim 1 wherein the marker comprises a suture.
 23. The deviceof claim 1 wherein the marker comprises a wire.
 24. The device of claim1 wherein the marker has a distinguishing mark.
 25. The device of claim1 wherein the marker is fixedly attached to the at least one body. 26.The device of claim 25 wherein the marker is woven to the at least onebody.
 27. The device of claim 1 wherein the marker is radioactive. 28.The device of claim 1 wherein the at least one body is radioactive. 29.The device of claim 1 wherein the at least one body is substantiallyspherical.
 30. The device of claim 1 wherein the at least one body issubstantially cylindrical.
 31. The device of claim 1 wherein the atleast one body is has a substantially irregular shape.
 32. The device ofclaim 1 wherein the at least one body is a biocompatible gel.
 33. Thedevice of claim 1 wherein the at least one body comprises a plurality ofpores.
 34. The device of claim 1 wherein the pores are configured topromote tissue growth in a preferred orientation.
 35. The device ofclaim 1 wherein the at least one filler body additionally comprises abio-compatible liquid.
 36. A subcutaneous cavity marking devicecomprising a plurality of resilient bioabsorbable filler bodies, atleast two of which are connected by at least one marker.
 37. The deviceof claim 36 wherein the at least one marker is suspended through theinterior of at least one of the plurality of filler bodies.
 38. Thedevice of claim 36 wherein the at least one marker is attachedsubstantially to an outer perimeter of at least one of the plurality ofbodies.
 39. A method of marking a tissue cavity comprising the steps of:(a) suspending a marker within at least one filler body of resilientbioabsorbable material, and (b) inserting the at least one filler bodyinto the cavity.
 40. The method of claim 39 wherein the step ofinserting the at least one filler body into the cavity is performedpercutaneously.
 41. The method of claim 40 wherein the at least onefiller body additionally comprises a hemostatic substance.
 42. Themethod of claim 40 wherein the at least one filler body additionallycomprises a pain-killing substance.
 43. The method of claim 40 whereinthe marker is radiopaque.
 44. The method of claim 40 wherein the markeris echogenic.
 45. The method of claim 40 wherein the at least one bodyis radiopaque.
 46. The method of claim 40 wherein the at least one bodyis echogenic.
 47. The method of claim 40 wherein the marker is fixedlyattached to the at least one body.
 48. The method of claim 39 whereinthe step of inserting the at least one filler body into the cavity isperformed surgically.
 49. The method of claim 39 wherein the step ofinserting the at least one filler body of resilient bioabsorbablematerial into the cavity is performed prior to the step of suspendingthe marker within the filler body.
 50. A method of marking a tissuecavity having a margin in a mammalian body, comprising: (a)subcutaneously accessing the cavity via a delivery device, (b) deployinga remotely detectable marker having a predetermined shape through thedelivery device into the cavity, wherein upon delivery into the cavitythe marker assumes a predetermined three-dimensional configuration so to(1) substantially fill the cavity, (2) mark the cavity margin, and (3)indicate the orientation of the marker inside the cavity.
 51. The methodof claim 50 wherein the marker is bioabsorbable.
 52. The method of claim50 wherein the marker is radiopaque.
 53. The method of claim 50 whereinthe marker is echogenic.
 54. The method of claim 50 wherein the markercomprises a wire.
 55. The method of claim 50 wherein the markercomprises a material selected from the group consisting of platinum,iridium, nickel, tungsten, tantalum, gold, silver, rhodium, titanium,alloys thereof, and stainless steel.
 56. The method of claim 50 whereinthe marker is capable of emitting radioactive energy.
 57. The method ofclaim 50 wherein the marker is a helical coil.
 58. The method of claim50 wherein the marker defines a volume having a substantially sphericalshape when the marker is deployed inside the cavity.
 59. The method ofclaim 50 wherein the marker defines a volume comprising a substantiallycylindrical shape when the marker is deployed inside the cavity.
 60. Themethod of claim 50 wherein the marker defines a volume comprising arandom shape when the marker is deployed inside the cavity.
 61. Themethod of claim 50 wherein the wire comprises a shape memory material.62. The method of claim 50 further comprising the step of introducing abiocompatible liquid in the marker prior to the step of deploying themarker.
 63. The method of claim 62 wherein the delivery device uses ahydraulic force to deploy the marker.
 64. The method of claim 50 furthercomprising the step of introducing a biocompatible liquid in the markersubsequent to the step of deploying the marker.
 65. The method of claim64 wherein the bio-compatible liquid is introduced to the marker via thedelivery device.
 66. A method of marking a tissue cavity comprising thesteps of: (a) inserting the at least one filler body into the cavity,and (b) suspending a marker within at least one filler body of resilientbioabsorbable material, and